Environmental Engineering Reference
In-Depth Information
dog) usually originate outside the building environment and are brought in
by passive transport. It is likely that some portion of symptoms reported in
problem and nonproblem buildings is due to classic allergy symptoms asso-
ciated with sensitization and subsequent exposure to pet allergens. The poten-
tial for such allergen-based problems can be elucidated by allergen testing of
surface dust samples and occupant allergy testing. Surface dusts can also
contain significant concentrations of phthalate plasticizers, which may con-
tribute to the development of an inflammatory response in the upper airways.
h. Hypersensitivity pneumonitis.
Outbreaks of hypersensitivity pneu-
monitis, as well as individual sporadic cases, occur in some problem build-
ings. Hypersensitivity pneumonitis can be diagnosed by its classic pattern
of flu-like symptoms, which are initiated early in the work week, improve
as the week progresses, and begin anew with the new work week or after
vacation. Exposures are often associated with contaminated HVAC systems,
and outbreaks may occur at the beginning of the heating season as microbial
slimes in condensate drip pans dry and aerosolize. Causal agents may
include thermophilic actinomycetes and mold species such as
Penicillium
or
Aspergillus,
which produce small spores. Cases may be confirmed immuno-
logically. Potential exposures to causal organisms may be evaluated by con-
ducting airborne sampling by culturable/viable and total mold spore meth-
ods for molds and actinomycetes, aggressive sampling in problem areas,
surface sampling, and visual inspection of infested materials and surfaces.
